A long range aim of this proposed work is to develop a clinical test based on patterns of neurotransmitters (monoamines, peptides/precursors, metabolites and conjugates) which can be used to guide and develop therapy and predict outcome in patients with trigeminal neuralgia (TGM) and other forms of facial pain. New technology interfacing up to 32 multiple electrode sensors with liquid chromatography (n-ELC) has improved the resolution and sensitivity of conventional LC techniques by approximately a factor of twenty, allowing simultaneous resolution of 100-200 compounds in directly injected cerebrospinal fluid (CSF) at the 0.5-1 pg level and simultaneous determination of most of the components of monoaminergic and peptide systems implicated in pain with a limited number of analytical conditions. The aims of the Phase I proposal are to refine methods for simultaneous determination of monoaminergic compounds and peptides; to provide an initial body of data on levels of monoamines and peptides in CSF from the trigeminal cisterns and posteria fossa of TGM and other facial pain subjects, and to compare the data within subjects for the two different sample types and among subjects for different diagnoses of facial pain for significant variations.